#import sys
s=set(['david',38,'zuoyu'])
t=set(['zuoyu',32])
print(s.union(t))
print(s.difference(t))
print(s.symmetric_difference(t))
print(s.difference_update(t))
print(s)
print(bin(15))
a=[1,5,3]
a.sort()
print(a)
a.sort(reverse=False)
print(a)
a.sort(reverse=True)
print(a)